Bernie Sanders is officially running for president. This time he starts in both a stronger and weaker position than he did when he first ran in 2016 — with high name recognition and strong popularity ratings, but in a very crowded field with lots of candidates eager to steal some of his left-wing thunder.

Sanders could win — indeed of the declared candidates, he is so far polling in first place.But to actually secure victory he will have to improve some serious deficiencies in his 2016 operation. He will have to run a tight campaign, deal with the age issue, summon forth a will to power, and above all improve his outreach to black and Latino voters.

Let's start with the last item. The importance of the black vote can be seen in the 2016 Democratic primary. Sanders got absolutely flattened by Hillary Clinton in the South (where black voters make up a huge share of the Democratic electorate), losing some states by upwards of 70 percentage points. It gave Clinton a huge delegate lead that eventually proved decisive. Sanders and his advisers undoubtedly know this and are reportedly working on it.

Now, contrary to 2016, when he was largely unknown among the black population, Sanders is extremely popular among black voters, pulling in +29 favorability in this group. But Joe Biden is even more popular (at least so far), if he decides to run. And Kamala Harris — who has already secured the endorsement of Rep. Barbara Lee (D-Calif.) — will no doubt be a strong challenger in this area as well.

However, the importance of the American Latino vote should not be underestimated either. It was not decisive in 2016 due to being more evenly split, but there are substantially more of them than African-Americans (18 percent against 13 percent, while non-Latino whites make up 61 percent). Furthermore, Sanders polls surprisingly well among Latinos, doing nearly as well as he does among blacks — better even than Biden.

Part and parcel with demographic outreach is running a tight campaign. Sanders was plainly not expecting to be able to win in 2016 and had spent the previous several decades as a bomb-throwing outsider. He had to scramble to put together a national operation, and tended to trust only his longtime allies who were not particularly experienced in national campaigning (as evidenced by the Southern wipeout). I have no idea how he is doing in this area, but time will certainly tell.

Ironically given his political priorities, one area where he will probably have no trouble is campaign cash. With his deep reservoir of committed small-dollar donors, he bested Harris' first day fundraising total in just four hours, with some 42,000 contributions.

Then there is the age question. Sanders will be 79 on inauguration day 2021, which would make him the oldest newly-elected president in American history by nine years. Age is not only a question of years, of course (just compare President Trump and Bruce Springsteen, who is only three years younger) and Sanders appears to be still in good shape both mentally and physically. Konrad Adenauer was an able chancellor of Germany up through age 87. Nevertheless, Sanders must at least think very hard about who his running mate would be.

Finally, there is the will to power. Today the American left faces the genuine possibility of obtaining top national power for the first time since the presidency of Franklin D. Roosevelt. It is much easier to point out deficiencies in reactionary Republicans or neoliberal Democrats than it is to reckon with the difficult business of overthrowing their power or accepting points at which compromise might be worth swallowing.

During his announcement interview with CBS's John Dickerson, Sanders questioned the utility of getting rid of the filibuster — which (if he is serious) would sharply restrict the ability of passing any of his hugely ambitious policy platform even if Democrats win a gigantic victory in 2020. He (and America itself) can't afford that kind of institutional timidity.

Perhaps more importantly, coming out on top of this super-crowded field will almost certainly require some ruthless tactics. All great politicians, from Lincoln to FDR to Barack Obama, do not hesitate to press the attack when victory requires it. So far Sanders has not displayed much in the way of a killer instinct — witness his gentlemanly dismissal of Clinton's emails issue. If he wants to win, he is going to have to fight hard. Certainly most of his opponents will have no compunction about doing so.

At any rate, the race is on. Whether Sanders will cap off his remarkable political rise with an ascent to the most powerful office in the world is largely up to him.